1. Field of the Invention
The invention relates to a driving device, in more particularly to a single phase motor driving device.
2. Description of the Related Art
A variety of heat dissipation apparatuses have been developed as the higher power consumption of the electronic components results in increased heat generation. A radiator fan, or a plurality of fans, controlled by a motor is the most common method of dissipating heat.
The specific operation of a single phase motor is set forth in the following description. FIG. 1 is a schematic view of a conventional single phase motor. As shown in FIG. 1, in a conventional single phase motor driving device, NPN bipolar transistor 2 and 4 drive the current to a single phase coil 6 toward a direction 12 based on the provided driving signal A and D. Thus, the collector-emitter path of the bipolar transistor 2, the single phase coil 6, and collector-emitter path of the bipolar transistor 4, are serially connected between a power supply VCC and a ground VSS. Similarly, NPN bipolar transistor 8 and 10 drives the current to the single phase coil 6 toward a direction 14 based on the provided driving signal C and B.
Consequently, the collector-emitter path of the bipolar transistor 8, the single phase coil 6, and the collector-emitter path of the bipolar transistor 10 are serially connected between the power supply VCC and the ground VSS. Thus, the bipolar transistor 2 and 4, and the bipolar transistor 8 and 10 are complementarily turned on and off, thereby controlling the rotation of the motor by changing directions of the driving current passing the single phase coil 6.
The single phase motor continues to rotate while the driving current is supplied by the power supply. When the single phase motor is obstructed or otherwise incapacitated, a gridlock/deadlock state occurs and the current flowing through the single phase motor from the power supply may overheat and burn out the single phase motor. The entire electronic system, including all components thereof, may be damaged from due to overheating. It is thus desirable to detect whether a single phase motor is in deadlock state, and effectively stop supplying driving current to prevent burnout of the single phase motor.